So, it's the end of the line for Henry Marsh. A career that began in many ways in Montreal at the 1976 Olympic Games will end in Seoul at the '88 Games. In the intervening 12 years, Marsh has married, fathered four children, graduated from law school, started a law career, changed careers, rose to become the world's best steeplechaser and then started the inevitable decline . . . . And now, at the age of 34, he is one, two, maybe three races away from retirement.

"The career has been great." says Marsh, "But it's time to move on."His wife of 10 years, Suzi, couldn't agree more. She has never made any secret of her longing for her husband's retirement from sport.

"Am I glad!?" she asks, rhetorically. "I'm 10 years worth of glad. How do you describe it? I'm speechless. We're going to celebrate. It's exciting just to see it in print, to see the whole thing unfold. It's been marvelous, but raising four children through 10 years through the ups and downs of his running has been challenging. It's all I've ever known our entire married life - his running and more children. It's been tricky juggling everything."

For all that, though, she has wanted it to end well, not prematurely, and anything short of the Olympics would have been just that. She fretted and cheered through three wild, precarious rounds during the U.S. Olympic Trials, as Marsh, who narrowly survived the semifinals, made the team.

"I've been training the last four years just for the Olympics," says Marsh. "It's the only reason I continued to compete. If I had medaled in '84, I probably would have retired. But I haven't fulfilled my dream of medaling in the Olympic Games. I didn't want to retire and wonder what I could have done if I had kept training."

Ah, yes, '84. You remember it well, right? Marsh being passed for third late in the homestretch; Marsh finishing fourth, the worst of all places; Marsh collapsing at the finish line, utterly exhausted; Marsh, lying prone on the track, his face wan and pale.

Marsh can never regain his lost opportunity of '84. He was 30 then, at the peak of his career, a gold medal favorite, but he he was devastated by a virus so persistent that he says he still has regular bouts with it. But in the wake of his great disappointment, Marsh never wavered; he was ready to commit to four more years. In Bud Greenspan's acclaimed movie "16 Days of Glory, Part II" the camera closes in for a tight shot of Marsh's face as he watches the medal ceremony for the steeplechase. Asked what he is thinking, Marsh says that he is going to go on, that he is not going to go out like this, that he will try for the Olympics again, that one is only a success if he gets up as many times as he falls.

And of course Marsh has fallen, sometimes literally, many times. His big-meet luck is already well chronicled - a disqualification in the World Cup, mono in another World Cup, the Olympic boycott in '80, a fall in the '83 World Championships, the virus in the '84 Games.

"If there's a race I'd like to do over again it's the '83 World Championships," he says. In that race Marsh was sitting just off the shoulder of the leader when he fell over the final barrier at the top of the homestretch.

But let none of these disasters overshadow Marsh's brilliant career. Consider his record: four times he has broken the American record, starting with 8:21.6 during his senior year at BYU and reducing it all the way to 8:09.17, the sixth fastest time in history; three times he has been ranked No. 1 in the world, and for a record 11 consecutive years times he has been ranked among the top 10 in the world - this in an event in which Americans previously were rarely, if ever, ranked at all; and four times he has made the U.S. Olympic teams, the last one as the oldest runner (and second oldest overall) on the squad.

"He's done what he vowed to do," says Suzi. "He really wanted most to make an additinal Olympic Team."

It hasn't been easy. "This was the most difficult of them all," says Marsh, who survived two bouts of viral pneumonia, poor early-season training and a fall in the semifinals of the Olympic trials to make it to Seoul.

And so one more Olympics. Some time during the Games, Marsh will run his last race, whether it's in the preliminary, semifinal or final round. Clearly, he is ready to accept retirement, and he began to realize it fully during last year's World Championships.

"As you go on you lose some of the excitement because you've been there," said Marsh earlier this summer. "I was very high for the World Championships in '83, but the excitement wasn't there in '87. I was amazed. I was burned out. It's hard to imagine - 12 years of getting sky high (for each race), but this time there wasn't the same sky-high excitement and nervousness. It was a signal that it wasn't there like it used to be. This year has been the same . . . it hasn't been a live-and-die thing for me like in '84."

Marsh, who quit his law career several years ago to pursue a business career with a more flexible lifestyle - the kind he has become accustomed to as a runner - actually finds he is anxious to pursue his work fulltime in the so-called corporate wellness field. He conducts seminars on fitness, stress management, nutrition, etc., for the Franklin Institute in Salt Lake City. "I've found something I look forward to doing, and that will really help my transition," says Marsh.

One senses that Marsh already has made the transition. During the past two years his athletic career has taken a nosedive, and it doesn't seem entirely attributable to age; only three years ago he ranked No. 1 in the world. Marsh himself concedes that his increasing interests outside of running have detracted from his training. This year his fastest time to date is only 8:24.21 - about nine seconds slower than the time he took into the last two Olympics. He has been picked by some experts to make the finals, but little else.

"His attitude is great: whatever will happen, will happen," says Suzi. "He's already reached the landmark of four Olympic teams. He's not a favorite to win the Olympics, so the pressure is off. If he does well, it will be unexpected; if he doesn't, that was what was supposed to happen. The stage is set the way Henry wanted it to be."